Preparation

Prep

20 m

Active

50 m

Ready In

1 h 10 m

In a small saucepan, heat oil, garlic, thyme, and oregano over medium-low heat for 15 minutes. If garlic starts to bubble, turn heat to low. Remove from heat. Let stand at room temperature until cool. Remove garlic and herb sprigs from the oil. Set aside 2 tablespoons of the oil. (Store the remaining oil in an airtight container in the refrigerator for up to 1 week and use in place of olive oil in recipes.)

Preheat oven to 425°F. Line two large baking sheets with parchment paper; brush paper with some of the 2 tablespoons herb-infused oil. Scrub potatoes. Use a mandoline to slice potatoes ⅛ inch thick. Arrange russet potato slices in a single layer on one of the prepared baking sheets; arrange sweet potato slices in a single layer on the other prepared sheet. Brush tops of potato slices with the remainder of the 2 tablespoons herb-infused oil.

Bake potatoes, one sheet at a time, for 24 to 26 minutes or until potatoes are golden brown, turning potato slices once halfway through baking. Check potatoes often during the last 2 to 3 minutes of baking since they will brown at different rates. Transfer any potato slices that are nicely browned to a clean piece of parchment paper on the counter. Sprinkle lightly with salt. Serve immediately.

Tip: Bruise herb sprigs by pressing with the flat side of a chef's knife or the back of a large spoon.